118 



THE WHITE RIVER BADLANDS 



ARTIODACTYLS 



As previously indicated the artiodactyls include those 

 herbivores in which the axis of the foot is between the third 

 and fourth digits. They nearly always have an even number 

 of toes on each foot, either two or four. None have less than 

 two. Occasionally three or five are present but this is dis- 

 tinctly exceptional. 



Artiodactyls have a long time constituted the domin- 

 ant ungulate order. They include a great assemblage of crea- 

 tures of many types but with marked unity of structure, the 

 size varying from the little chevrotain to the huge hippopo- 

 tamus. They have always been most abundant in the old 

 world, nevertheless they have had from near their beginning 

 a good representation in North America and the White River 

 badlands have disclosed a remarkably interesting series. 

 Practically all of these White River forms are described in 

 the following pages. 



ELOTHERIDAE AND DICOTYLIDAE 



Few fossil animals of the White River badlands have 

 afforded more real puzzling features than the ancestral swine 

 (giant pigs). Several genera and a number of species have 

 been identified, including several classed as ancestral pec- 

 caries, but usually the material is fragmentary and con- 

 fined mostly to the head and lower jaws. Elotherium is the 

 best known genus, its skeleton being represented by consider- 

 able material. It was evidently a very grotesque animal. 



Figure 55 — Skull and lower jaws of Dinohyus hollandi. 

 1906. 



Peterson, 



